In a conventional magnetic storage device such as a floppy disk drive, there has been employed a magnetic head of a combined type consisting of a recording/reproducing head for the execution of recording and reproducing with respect to a magnetic recording medium such as a floppy disk and an erasing head for erasing a track on the magnetic recording medium on which information had been recorded by the recording/reproducing head.
Such type of combined magnetic head comprises a combined magnetic core, and a slider for holding the combined magnetic core, the combined magnetic core being in sliding contact with the surface of a magnetic recording medium in cooperation with the slider. The combined magnetic core includes a recording/reproducing core and an erasing core each consisting of an outer core and an inner core, the recording/reproducing core being secured to the erasing core by a glass adhesive in such a manner that respective inner cores confront each other. The recording/reproducing core of the combined magnetic core has at its one end a recording/reproducing gap, while the erasing core has at its one end an erasing gap.
On the other hand, the slider is integrally molded into a substantially rectangular container having a bottom including a surface in sliding contact with the magnetic recording medium. The slider further includes at its bottom a core slit adapted to receive the combined magnetic core and opening to the sliding contact surface.
The combined magnetic core is inserted into the core slit of the slider and is held in place and securely fastened thereto using a sealing glass, for example, in such a manner that a recording gap and an erasing gap are exposed to the sliding contact surface. A recording/reproducing coil assembly and an erasing coil assembly are mounted to the recording/reproducing core and the erasing core, respectively, of the combined magnetic core which is firmly held within the slider in this manner, and then a back core is mounted to the open end of the combined magnetic core. The slider which has thus accommodates the combined magnetic core, the coil assemblies, and the back core is then attached to a carriage arm by way of a gimbal spring.
It is to be noted that such type of combined magnetic head must be fabricated with a significantly high accuracy so as to ensure a high-density recording. Accordingly, the combined magnetic core must be accurately positioned and held within the core slit of the slider.
In a combined magnetic head which has been already proposed by the present inventors (Japanese Patent Application No. 3-297502), a plurality of positioning protrusions for the determination of the position of the combined magnetic core are formed on the inner surface of the core slit of the slider, and a pair of anti-slant noses to prevent slanting or tilting, of the combined magnetic core are formed on side walls extending in the longitudinal direction of the core slit of the slider, respectively, each nose confronting the other. The anti-slant noses projecting toward the core slit from the middle of the inner surfaces of the slider side walls serve in cooperation to prevent slanting of the combined magnetic core by clamping the respective inner cores of the recording/reproducing core and the erasing core of the combined magnetic core.
It is however very difficult to integrally mold the slider with high accuracy in such a manner that the confronting surfaces of the anti-slant noses resting on both sides of the slider are brought into close contact with the combined magnetic core without any gap since the heat shrinkage percentage of the material is relatively large and the core slit is subjected to a deformation due to the weight of the slider itself at the time of shrinkage. As a result, the combined magnetic core which has been inserted into the core slit undergoes an inclination which may prevent the accurate positioning of the combined magnetic core with respect to the slider.
Moreover, in proportion to the area of the confronting surfaces of the respective anti-slant noses of the integrally molded slider, there is an increase in the frequency of occurrence of micro-protuberances which are created thereon by foreign matter. Such micro-protuberances may block the insertion of the combined magnetic core between the two noses.
It is therefore an object of the present invention to overcome the deficiencies involved in such conventional combined magnetic head and to provide a combined magnetic head having a slider within which a combined magnetic core can be accurately positioned and held in place.